Capacitive SensorThe purpose of this circuit is to animate shop-windows by means of a capacitive sensor placed behind a post-card-like banner.http://www.redcircuits.com/Page22.htm

Compass Sensor kinds of magnetometers able to read such a weak magnetic field strength, Earth's magnetic field,K MZ 51,Electronics,Sensor-support, Programhttp://www.restena.lu/convict/Jeunes/CompassSensor.htm

Electromagnetic Field DetectorOrdinary headphones are used to for detection, surrounds a transformer is heard , Mains wiring buried an inch in plaster can be detected with precision.http://www.zen22142.zen.co.uk/Circuits/Misc/emf.htm

Fridge door AlarmIt beefs after you leave the open door in 20 secondshttp://www.redcircuits.com/Page15.htm

Motor Control Sensor Feedback CircuitsPopular current-sensing sensor because of their low cost and good accuracy.http://ww1.microchip.com/downloads/en/AppNotes/00894a.pdf

Touch plateTHE HIGH GAIN AMPLIFIER,Build the circuit and learn how it works, Our circuit is amplifying the current flowing through your finger, HOW THE CIRCUIT WORKShttp://www.talkingelectronics.com/FreeProjects/5-Projects/Page14.html

VOLTAGE-BASED CONTROLLER FOR SWITCHESSimple circuit for controlling four switches from a distance through just a pair of wirehttp://www.electronicsforu.com/EFYLinux/circuit/july2003/cir5-voltage.pdf

SENSITIVE VIBRATION DETECTORApplications is in a rolling shutter guard for offices and shops. with complete details on how to build the project.http://www.electronicsforu.com/EFYLinux/circuit/nov2005/CI-06_Nov05.pdf

Pressure sensorIndustrial applications such as air conditioning, liquid level sensing and flow control.http://www.jandspromotions.com/wirelesschallenge/appnotes/AN1082%20-%20Pressure%20Sensor.pdf